It is generally known to employ oil-containing compositions for treating and cleaning various surfaces. Such compositions have been in various forms, including pastes, solutions, lotions, creams and emulsions. Numerous surfactants or emulsifying agents are known for preparing oil-in-water emulsions and water-in-oil emulsions. Condensation products of diethanolamine with long chain monocarboxylic acids as disclosed, for instance, in Kritchevsky U.S. Patents No. Re 21,530 and 2,089,212, are used commercially as detergent surfactants and as other surfactants in a number of industries. U. S. Patent No. 4,330,422 to Tesch relates to a surface treating composition especially suited for cleaning and treating stainless steel comprising an aqueous emulsion of white mineral oil wherein a preferred emulsifier comprises fatty acid alkanolamides. U. S. Patents Nos. 4,439,342-344 and 4,483,783 to Albanese relate to surface covering emulsions including a dispersal agent consisting of cocodiethanolamide. Similarly, U.S. Patent No. 3,387,008 to Cawley relates to alkanolamides of fatty acids having particular utility as surfactants. It is generally known in the art, however, as taught by Cawley, that monoester amides and diester amides are poor surfactants.
Many condensation products of diethanolamine with long chain monocarboxylic acids have disadvantages which impair their use as surfactants in water-in-oil and oil-in-water emulsions. For example, some fatty acid diethanolamide compounds are known to rearrange to the corresponding fatty acid diethanolamine ester at slightly elevated temperatures and thus detrimentally affect the ability of the amide-containing composition to perform as an emulsifier. Other condensation products of diethanolamine with long chain monocarboxylic acids are difficult to prepare in a form which is uncontaminated by other side products which detrimentally affect the emulsifying properties. Finally, amide ester and amide diester condensation products have been generally known to be poor surfactants due to their increased hydrophobicity and decreased water solubility. These characteristics make it unexpected that amide ester and amide diester condensation products would be useful in surface-treating compositions, especially in view of their hydrophobicity.